Shall Lists
Slide 1
Shall List Statement Categories
 Functional Requirements
 Non-Functional Requirements
Slide 2
Non-functional Requirements
 Performance
•
speed, capacity, reliability
 Security
•
more than just access control
 Operational
•
physical and technical environment in which system will
operate
 Cultural and Political
•
includes social and legal aspects
Slide 3
Another Classification: FURPS
 Functionality
 Usability - human factors, aesthetics, consistency
of user interfaces, help, documentation
 Reliability – frequency/severity of failure,
recoverability, predictability, accuracy
 Performance - response time, throughput,
availability, resource usage, resource consumption
 Supportability – testability, extensibility,
adaptability, maintainability, internationalization,
configurability, installability, scalability, etc.
Slide 4
FURPS+ : Constraints
+ implementation –resource limits, languages, tools,
computing platform, standards
+ interface – imposed by interfacing with external
systems
+ operations - system management, in its operational
setting
+ packaging/physical – shape, size, weight
+ legal - licensing (patents, copyright, regulations)
+ design – e.g, a relational database is required
Slide 5
Yet Another




Performance Requirements
Security Requirements
User Interface Requirements
Qualification Requirements
Slide 6
Functional Requirements
 The system shall calculate interest on a daily basis.
•
For a loan given to a producer, the system will calculate
interest daily based on the prime rate of +1.2
 The system shall log all employee name change.s
•
The system will write an entry to the audit log file after
any modification of an employee name.
Slide 7
Interface Requirements

The system shall record an acknowledgment when a new
employee is created into the XYZ table.

The XYZ system shall use these records to update the
time stamp of an employee record.

The system shall mail the month-end report message to the
"Director" at each month-end.This E-mail is used to
manually load data into the Director’s system.
Slide 8
Performance Requirements
 The system shall perform simple queries (e.g. no
more than 2 tables) in less than 10 seconds.
•
This speed is required to ensure better service to the
public requesting information on the XYZ system.
 Month-end runs will take no longer than 24 hours
•
Weekly backups are performed every Sunday at 6:00
a.m.; if the month-end process takes too long, it will
affect the operations of other systems such as
AAFC.12
Slide 9
Qualification Requirements
 The system shall be user friendly.
 The system will be used by non-technical
users, and thus must be simple and easy to
use.
 The system shall require little training.
 Help menus will be available for all on-line
query screens.
Slide 10
Shall List Testability Types
 Demonstration:
•
Demonstrate the operation of the function to the system
owner to show that the requirement has been met.
 Inspection:
•
Sometimes used in combination with demonstration, it
requires visual examination of the code documentation,
table dumps, scans, etc.
 Analysis/Special Qualification:
•
The processing of accumulated data obtained from other
methods, or any special tools, techniques, procedures,
facilities, and acceptable limits. This type of testing
usually affects critical parts of the system and/or
interfaces.
Slide 11
Shall List Testability
Requirement
Testing
The system shall be user
friendly
Demonstration
Month-end runs will take no Inspection
longer than 24 hours
Transfer of data shall be
at a rate of 9600 baud
Analysis
Slide 12
Helpful Hints
 Sentence Structure
•
Keep your sentences short and simple. It doesn't
matter if specifications read like a grade-school
textbook. We're not trying for a Pulitzer Prize.
 Mind your Grammar
•
Grammatical errors can affect the intelligibility of
the sentence.
 Keep statements unambiguous
•
Many words have multiple meanings. Statements can be
even more ambiguous.
Slide 13
Shall List Format
 Each requirement is something that the
system SHALL do.
 Each requirement must unambiguous and
testable
• Very precise language from which the design
will be developed
• You should be specifying tests at this point,
also.
Slide 14
Remember the V-model
Slide 15
Shall List Format - Examples
 The system shall allow the librarian to check out
items of any type except periodicals.
 The system shall generate a due date of 7 days
from the date checked out for each item.
 The system shall update the member’s checkout
history with the date checked out and Call
Numbers checked out.
Slide 16